This invention relates to seat systems and, more particularly, to systems intended to provide long term seating with minimal formation of decubitous sores, and other physiological disorders which occur as a result of long term seating such as nerve, muscle and skeletal disorders.
The problem of preventing the formation of decubitous sores is particularly difficult in patients who are required to sit for long times, especially in wheelchairs. In this position, a person's weight is greatly concentrated in the buttock area and there is a natural tendency for decubiti to form in the tissue under the ischial bones and the coccyx. One has only to consult the trade literature to realize that numerous attempts have been made to solve this problem. There are a great many different seat systems reflecting these efforts and various degrees of success have been achieved.
One fundamental approach taken by many who have attacked this problem is to relieve the pressure under the seat bones and redistribute it to the surrounding areas of the buttock and thighs. That too is the fundamental approach taken with the subject invention. Most if not all, prior attempts to solve this problem have employed the philosophy that at least some pressure can be tolerated under the seat bones. The philosophy of the subject invention, however, is to eliminate that pressure virtually in its entirety, but without producing unacceptably high pressures elsewhere. In fact, as will be mentioned later, the subject invention results in essentially zero pressure under the ischial bones and the coccyx while pressure readings at surrounding areas of the buttock are sufficiently low to permit adequate blood circulation in the capillaries contained therein, even in the trochanteric area. This invention thus results in an achievement not found in prior art devices.